This invention relates to an apparatus for recording and displaying or plotting graphs obtained as a computer output, comprising a computing unit for sequentially generating the points of the graphs, a read-write operating memory for storing said graphs and means for displaying or plotting a graph so stored.
There are known apparatus for recording graphs to be displayed, for instance on a CRT. In a known apparatus, a device for reading the graph on the memory line by line controls a graph tracer to display the entire graph in a single reading, thus preventing the tracer on the paper to be moved with frequent reciprocations.
Since the storing of a graph, in form of points of a matrix codified according to the binary system, requires a big capacity of the memory, an apparatus has been already proposed, wherein the data of the graph in the memory are compacted by recording the points or blanks with a code representing the number of adjacent similar points or blanks. However, this apparatus requires (for compacting the graph) a processing operation, in addition to the operation for generating the graph, which is very intricate and expensive.